Somatic mutations in oral squamous cell carcinomas in 98 Japanese patients and their clinical implications

KMT2 (MLL) family of methyltransferases in head and neck squamous cell carcinoma: A systematic review

BACKGROUND

The involvement of the KMT2 methyltransferase family in the pathogenesis of head and neck squamous cell carcinoma (HNSCC) remains elusive.

METHOD

This study adhered to the PRISMA guidelines, employing a search strategy in the LIVIVO, PubMed, Scopus, Embase, Web of Science, and Google Scholar databases. The methodological quality of the studies was assessed by the Joanna Briggs Institute.

RESULTS

A total of 33 studies involving 4294 individuals with HNSCC were included in this review. The most important alteration was the high mutational frequency in the KMT2C and KMT2D genes, with reported co-occurrence. The expression of the KMT2D gene exhibited considerable heterogeneity across the studies, while limited data was available for the remaining genes.

CONCLUSIONS

KMT2C and KMT2D genes seem to have tumor suppressor activities, with involvement of cell cycle inhibitors, regulating different pathways that can lead to tumor progression, disease aggressiveness, and DNA damage accumulation.

TERT promoter mutation positive oral cavity carcinomas, a clinically and genetically distinct subgroup of head and neck squamous cell carcinomas

BACKGROUNDS

The importance of TERT promoter (pTERT) mutation of oral cavity squamous cell carcinoma (OCSCC) with clinical features and genetic alterations are not well recognized.

METHODS

We retrospectively analyzed genetic data from multiple databases, including 260 cases from the C-CAT database, 407 cases from the MSK-MetTropism database, and 40 OCSCC datasets from in-house clinical samples.

RESULTS

From C-CAT database, TP53 (66%), CDKN2A (51%), and pTERT (29%) were the most frequent mutations observed. pTERT mutations were more prevalent in OCSCC (63%), younger individuals, and women (46%), with lower rates of alcohol abuse and smoking and co-mutated with TP53, HRAS, and CASP8. MSK-MetTroposim data validated with the enrichment of pTERT mutations in OCSCC, among women and Asian individuals. In-house datasets OCSCC with pTERT mutation (50%) characterized by fewer recurrent neck metastases.

CONCLUSION

The study suggests that OCSCC with pTERT mutation represents a distinct subgroup with unique clinical and genetic characteristics.